Process for the separation of stereoisomeric mixtures into their components and components obtained hereby

ABSTRACT

A process for the resolution of stereoisomeric mixtures of certain steroids obtained by synthesis into its components, comprising subjecting the stereoisomeric mixture to gel filtration, the components in view of different retention volumes being separated and being separately recoverable; and stereoisomeric components A and B thereby obtained, pharmaceutical compositions thereof; and method of treating inflammation therewith.

United States Patent n91 Brattsand et al.

[21] Appl. No.: 359,913

[52] US. Cl 260/23955 D [5|] Int. CU C07J 17/00 [58] Field of Search 260/23955 D [56] References Cited UNITED STATES PATENTS 3,048,581 8/1962 Fried 260/239.5S 3,128,238 4/1964 Mallett 195/51 3,133,940 5/1964 Oughton et al. 260/397.4S

FOREIGN PATENTS OR APPLICATIONS 778,364 2/1968 Canada 260/56 51 Dec. 23, 1975 8/l963 United Kingdomumu. zen/239.55 D

OTHER PUBLICATIONS Leitch et al., J. of Chromatography, Vol. 28, pp. 132-134, (I967).

Baezuk et al., J. of Chromatography, Vol. 60, pp. 351-361, (I971), Sephadex, G-IO & 6-15.

Helzog et al., Tetrahedron, Vol. 18, 1962, pp. 581-586.

Buzby et al., Jour. Medicinal Chem, Vol. 10, 1967, pp. 199-202.

Primary ExaminerElben L. Roberto Attorney, Agent, or FirmG0rdon W. Hueschen ABSTRACT A process for the resolution of stereoisomeric mixtures of certain steroids obtained by synthesis into its components, comprising subjecting the stereoisomeric mixture to gel filtration, the components in view of different retention volumes being separated and being separately recoverable; and stereoisomeric components A and B thereby obtained, pharmaceutical compositions ther'edf; and method of treating inflammation therewith.

23'CIaims, No Drawings PROCESS FOR THE SEPARATION OF STEREOISOMERIC MIXTURES INTO THEIR COMPONENTS AND COMPONENTS OBTAINED HEREBY The present invention refers to a process for the separation of a stereoisomeric mixture of certain steroids obtained by synthesis into its components, below called component A and component B. The invention also refers to stereoisomeric components A and B thereby obtained, pharmaceutical compositions thereof and method of treating inflammation therewith.

It is a well-known fact that mixtures of stereoisomers having the same molecular weight and in other respects possessing practically identical solubility characteristics may be extremely difficult to separate. It is, therefore, highly surprising that in conformity with the present invention it has been shown possible to separate the stereoisomeric components by gel filtration. The gel filtration technique is normally used to separate molecules having a lower molecular weight from molecules having a higher molecular weight. Stereoisomers, the molecules of which have the same molecular weight, are therefore not expected to have the same retention volume in gel filtration in view of which they would thus not be separable by this procedure. Therefore, it was most surprising that the stereoisomeric components A and B having the same molecular weight may still be separated with excellent result using this procedure.

The separation process according to the present invention has made it possible to investigate the physiological characteristics of the separated stereoisomeric components. In this connection it has surprisingly been found that one of the stereoisomeric components, component B, has consistently physiologically better characteristics than the other stereoisomeric component, component A, and that it is also better than the original mixture in this respect. Thus it is possible by the process of the present invention to prepare in a pure form new stereoisomeric components, which have certain advantages over the original synthetic stereoisomeric mixtures.

More precisely, the present invention refers to steroids having the general formula:

wherein the 1,2 and 4,5-positions are saturated or a double bond is present in at least one of said two positions, R is a straight or branched alkyl having l-IO, preferably l-6 carbon atoms, X and X, are indepen- 45 dently selected from hydrogen and fluorine, X, being 50 group. The individual stereoisomeric components present in a mixture of a steroid having the above formula I may be elucidated in the following way:

and

In the above formulas the stereoisomeric components dilTer from each other with regard to the space orientation about the 2'-carbon atom in the dioxolane ring.

As introductorily indicated the process according to the invention consists in subjecting a stereoisomeric mixture or a stereoisomeric pair of steroids having the above formula I to gel filtration, the stereoisomeric components A and B being separated in view of different retention volumes and being separately recoverable. The gel filtration may be carried out on many different types of gel materials. One type of such mate rials is hydroxypropylated cross-linked dextrane gels of the type Sephadex LH, for instance Sephadex LH sold by Pharmacia Fine Chemicals, Uppsala. Sweden,

resulting in a good fractionation within the molecular weight range l00-4000. Another useful gel type consists of copolymers of vinyl acetate having such exclusion limits as to be useful in the molecular weight range up to about 1000. One such vinyl acetate gel useful in this connection is Merckogel, type OR PVA 2000 sold by AG E. Merck, Darmstadt. Western Germany. The gel material is used in equilibrium with a suitable solvent. As an eluting agent halogenated hydrocarbons, ethers or esters or mixtures thereof, may be used. and chloroform, methylene chloride, ethylene chloride tetrahydrofurane. dioxane and ethyl acetate have been used successfully. Hereby an excellent separation of stereoisomer A from stereoisomer B will be obtained, and the stereoisomeric mixture A. B may, of course, also in an excellent way be removed from by-products formed in the steroid synthesis.

in formula 1 above the hydroxyl group in 2 1 -position may be esterified with a fatty acid. Such fatty acid may have a straight or branched hydrocarbon chain and preferably contain l-l 2 carbon atoms. As examples of suitable acids acetic acid, propionic acid, butyric acid, valeric acid. isovaleric acid. trimethyl acetic acid, hexanoic acid, tert.-butylacetic acid, octanoic acid may be used. It may also be esterified with a heterocyclic carboxylic acid. for instance pyridine--3-, pyridine-4, and benzofurane-2-carboxylic acids: or mcnthoxymethyl carboxylic acid. For the preparation of water-soluble derivatives the esterification may be carried out with dicarboxylic acids having preferably 2 to 12 carbon atoms, or with phosphoric or sulphuric acids.

The steroids l in the form of cyclic acetals may be synthesized in a manner known per se starting from the loa, l7a-dihydroxy steroids and an aldehyde in the presence of an acid catalyst. for instance perchloric acid, p-toluene, sulphonic acid, hydrochloric acid etc. in dioxane or another suitable solvent. The reaction results in a mixture of stercoisomers. A and B. having the same molecular weight and practically identical solubility characteristics. and the stereoisomers have been found to be extremely difficult to separate by conventional methods for the separation of stereoisomers. for instance by recrystallization.

The invention will now be further illustrated by nonlimiting examples. In the examples there is used for the chromatography a column having a length of 85 cm, an inner diameter of 2.5 cm, the flow rate being i ml/min. The retention volumes given in the examples refer to chloroform as eluting agent.

In the gel filtration on the column it has been found to be easier to separate the by-products from the isomeric mixture in the crude product than to separate the isomers from each other. since the former show greater differences in retention volumes than the latter. It has also been found that the solubility of the crude product as well as the solubility of the purified isomeric mixture decreases, whereas the separation degree increases with decreasing polarity of the solvents used. This is particularly true with regard to the derivatives substituted with a shorter side chain on the 2-carbon atom of the dioxolane ring. In the chromatographic separation of the examples below it has therefore turned out to be advantageous first to separate the isomeric mixture from the by-products of the crude product by means of a somewhat more polar solvent and then to separate the isomers from each other by means of a solvent possessing a lower polarity. This results in several advantages. Firstly. the whole capacity of the column may be utilized and great amounts of crude product may be freed from by-products in each application. Secondly. a possible partial use of the column capacity resulting from limitations in the solubility of the isomeric mixture in the solvents having a lower polarity may be compensated by making new test applications on the column at relatively short intervals day and night without awaiting the previous application to leave the column. The solvents which have been found to be highly active in the pre-separation, such as methylene chloride, ethylene chloride. tetrahydrofurane and ethyl acetate, have also given a completely satisfactory isomeric separation, whereas chloroform and dioxane have 'given an even better result with regard to the isomers most difficult to separate.

In all examples the molecular weights are determined by mass spectroscopy. and in all NMR-investigations tetramethylsilane has been used as an internal reference. All melting points have been determined by means of a Reichert melting point microscope.

EXAMPLE 1 l6a, l7a-l2'-Hydrogen-2-methyl)methylene dioxy-9-fluorpregnal .4-dienc- 1 I13, 2l-diol-3.2U-dione.

To a solution of l l2.0 mg newly distilled paraldehyde and 0.2 ml 72 /c perchloric acid in 75 ml well purified and dried dioxane 500.0 mg of triamcinolon were using. in addition to chloroform and methylene chloride. ethylene chloride. ethyl acetate. tetrahydrofurane and dioxane as eluting agents on both types ofgel materials.

EXAMPLES 2-l5 Analogous to the process described in Example 1 different isomeric mixtures were prepared. the isomers given in Table l below being obtained by means of separation according to Example I. The NMR-investigations were carried out in CDCL, if not otherwise stated.

Table 1 Ex. The l6a.l7u-deri\'ative lsumer la|,,-"" Mp Molecular weight lit-CH Retention Nov of with [c=0.2 in (Cl found calculated 5 (ppm) volume (ml) CH- .Cl.

2 triamcinolone propionaldehyde A 85. l 204-7 434 434.5 0.99 840-862 B H l2.7 (9-92 0933 924-990 3 n-hutyraldchyde A 77.5 l50-5 448 443.5 l.ll 822-876 B +l05.5 147-50 0.93 9l2-984 4 n-valeric aldehyde A 73.7 l23-7 462 462.6 099 780-801 B 936 l02-6 0.9] 864-924 5 n-caproic aldehyde A 70. l l72-9 476 4766 l.00 702-733 B 979 lliU- 5 0.93 "IX-32K 6 n-decyl aldehyde A 63.6" l6l-4 532 532.7 0.99 540-245 B +9l.3 l47-52 (L93 595-648 7 l'luocinolone acetaldehydc A 7 l l 232-5 438 438.5 0.88" 1200-1250 B +l l0.ll 224-7 0.243 l260-l350 X n-butyraldehyde A 69.0 l96-200 466 466.5 0.98 l l30-l I90 B +94.5 169-72 0.93 l225-l320 9 ncaproic aldehyde A 65.9 l43-7 494 494.6 098 870-930 B 917 l67-70 0.92 96ll-l0l5 l0 n-caprylic aldehyde A 6| .0 l66-9 522 522.6 098 735-765 B 88.2" l24-7 093 790-850 I l 1 l8. l6a. I711. acetaldehyde A +l44.8 l77-li5 404 404.5 0.98 396-4l4 2 I -tetrahydroxy-4- pregnene- 3.2(l-dione B +l64.6 202-[0 0.9] 432-453 l2 prcdnacinolone n-butyraldehyde A 85.6" 225-28 430 430.5 0.99 450-68 B +l05.3 259-60 0.93 510- l3 n-eaproic aldehyde A 72.9" 198-201 458 458.6 0.99 414-32 B +l04.5 167-71 093 462-98 l4 n-caprylic aldehyde A 67.6 l69-73 4K6 486.7 0.99 355-365 B 963 l43-46 093 385-400 I 5 n-decyl aldehyde A 66.0 l57-66 5 l4 5 l4.7 0.99 330-350 B 912 l24-7 0.93 365-385 "mason.

chloride as an eluting agent. This resulted in 431.7 mg EXAMPLE 16 (81 "/v) pure isomeric mixture having the following characteristics: Melting point about 207-222C; [01],, l07.2 (e=0.3 in CH CI molecular weight =42O (theor. 420.5).

The isomeric mixture (338.2 mg) was rechromatographed on a column packed with Sephadex LH 20 and using chloroform as an eluting agent. Two different isomers, A and B. of 160:, l7a-(2'-hydrogen-2-methyl) methylene dioxy-9-fluorpregnal ,4-diene-l lB-diol- 3.20-dione were obtained in the following yields and having the following characteristics: A: [23.4 mg (37 melting point 2l7-l9C; [11],, +87.5 (c= 0.3 in CH- Cl molecular weight 420 (theor. 420.5) (Retention volume 920-990 ml). B: 194.7 mg (58 melting point 224-28C; [0],, +l20.8 (c= 0.3 in (:H2CI3); molecular weight 420 (theor. 420.5) (Retention volume [020-1 100 ml). The isomer purity 98 7: of A and B was determined by NMR spectroscopy by studying the signal for lit-CH positioned at 8 L00 ppm (CD0 for A and at 5 0.92 ppm (CDCl for Similar separation results have been obtained by using a gel of copolymers of vinyl acetate (Merckogel OR-PVA 2000 molecular weight range up to 1000; AG Ii. Merck. Darmstadt. Western Germany as well as by Resolution of 16a, l7a-( 2 -hydrogen-2'-methyl )methylenedioxy-l IB- hydroxy- 2 l benzofurane-Z-carbonyloxy )-9-fluorpregna-l,4-diene-3,20-dione into isomers.

A solution of 60 mg pure isomeric mixture of 16a, l7a-( 2'-hydrogen-2'-methyl )methylenedioxy-Q-fluorpregna-l.4-diene-lla, 2l-diol-3.20-dione in 2 ml of dry pyridine was added to 72.2 mg benzofurane-2-carboxylic acid chloride dissolved in 1 ml dry dioxane. The reaction mixture was allowed to stand under stirring at room temperature over night, the major part of the solvents were evaporated in vacuum and the residue was poured into 30 ml of 3 ammonium chloride solution. The precipitate obtained was separated by centrifugation and dissolved in ml of chloroform. The chloroform solution was washed once with 5 sodium carbonate solution. three times with water, dried over magnesium sulphate and evaporated in vacuum. The residue was chromatographed on Sephadex LH-20 using chloroform as an eluant. Two different isomers. A and B. of 16a, l7u-(2'-hydrogen-2'- methyl )methylenedioxy-l lB-hydroxy-2 l benzofurane-Z-carbonyloxy )-9-fluorpregnal .4-dione-320- daonfe ere obtained in the following yields and having cmmued t e o owlng character stlcs. EmmEle 3| Linimem, A: 28.1 mg (35%); meltlng pomt 250-56C; [01],, Steroid 0.001 -0 2 l58.9 (c 0.2 in CH Cl2); molecular weight 564 g earn (theor. 564.6). Retention volume 270-90 ml. F 5 pmymymhylcne whim" B: 24.2 mg melting point 24750C; [01],, m no r lv 2 l68.3 (c =02 in c100 molecular weight 564 ;,';g5;*' 3:; (theor. 564.6). Retention volume 300-610 ml. Mctagin 0.0x

. II The 1somer purlty 98%) of A and B was deter- PmPdP v 10 Water to 100g mlned y M p py y y g the Slgna] for methylester of parahydruxybcnvoic acid l8-CH posmoned at 5 [.06 ppm (CDCl for A and n m i' q o rwmhydrflxybcnmic E r K at 8 1.03 ppm (CDCl;,) for B. i um 1 5m t BI'OI m Slmlliil separat1on results have been obtamed by Ethan, w ml g using Merckogel OR-PVA 2000, as well as usmg, 111 Example 33-51181261109"lflrinieclilmaddition to chloroform, methylene chloride, ethylene 5 P 1; hi -d h l h d f 1 I d Sodlum carhoxymcthyl cellulose 7 mg c. on e, et y acetate, tetra y ro urane an d1oxane Sudium Chkmdc 7 mg as elutmg agents on both types of gel materials. Twven U5 s Phcnyl carhinol 8 mg Water, sterile to I mg polyoxycthylenetZlljsorhitan munoolcatc. DilTerent 2 l -esters of the isomeric mixtures prepared L 34 a "l according to Examples ll 5 were prepared analogous g I u to the process described in Example 16. By analogous Na-cetyl stcaryl alcohol 0.2 purification and separation the isomers given below in St) I'U I11 'l'lfi i] C a Table 2 were obtamed. The NMR-lnvestlgatlons were z (H carried out in CDCl;,. a d

- I clra unr ichlnrncthanc/ The acid chlondes used for the esterlficatlon are dmuordichlmumcmunc 1nd1cated 1n Table 2 1n the following manner. NAC m 1: nicotinic acid chloride, AAC acetyl chloride, VAC valejnchzlrcicilchlonde, BAC =benzofurane-2-carboxylic m AS will be Clear from the fnuowing prescmation of C on experimental results, one of the stereoisomeric compo- Table 2 Ex the 2l-cstcr lsomer [01],, Mp. Molecular Iii-CH Retention vol. Nu. of isomeric mixture (c=().2 in "C weight fitppm] (mlsl according to CH Cl,) found: calcu- Ex. Nu. with latcd:

17 1 NAC A +1210 268-70 525 525.0 1.07 340-05 B +1350 275-7 1.03 375-4 to 11 1 VAC A 70.0" 2424-51 504 504.6 1.00 276-306 B +1024" 201-4 097 3121-354 19 1 AAC A 872 235-11 402 402.5 0.90 325-55 B +1 1 10 259-03 0.93 3610-90 20 3 BAC A +139.1 135-45 592 592.7 1.07 250-75 B +157.s 205-12 1.03 2110-3211 21 3 NAC A +102.0 207-10 553 553.0 L07 320- B +132.9 252-4 104 350-240 22 3 VAC A 070 170-1 532 532.7 100 255-210 B 977 254-0 0.97 2x5-310 23 7 BAC A +1436 147-52 5142 582.6 1.00 2101-320 B +104.4 274-21 1.02 325-05 24 7 AAC A 797 31 1-4 4240 480.5 0.99 366-90 8 +1010 322-5 0.95 402-38 25 s BAC A +1291 129-34 010 010.7 1.05 270-94 3 +1470 208-10 103 300-30 20 a VAC A (10.8 212-10 550 550.7 0 9x 2511-112 0 215.7 01-63 550 550.7 095 288-324 27 1: AAC A 110.2" 176-) 472 472.0 11.99 235- B +97s ltH-fi 090 250-75 2:: 12 BAC A +1420 101-23 574 574.7 100 200-25 Below there are given examples of gelenic preparanents, component B, has consistently physiologically tions prepared in a conventional manner: superior characteristics as compared to the other stereoisomeric component and the stereoisomeric mixture. Example 21; Gimme m unhvdmm The stereoisomeric component B being the more act1ve Steroid 0001-02 one of the two components A and B in the stereoiso- C t 5 meric pair, may be defined as the stereoisomeric com- Liquld puraffin 20 h h h I, I Whaling m mug ponent s owing t e 1g est re ative rotary power. It Example 30. Cream. connection with gel filtrat1on sa1d component may also 3 22 be defined as the stereoisomer, which in the gel filtrag tion shows the greatest retention volume, i.e. it leaves Vaseline 42 last with the eluate. Finally, said active stereoisomeric 0.3 component may be defined as the component which in Sodium citrate 0.9 Water to g NMRrmeasurements shows the lowest S-value for 18- CH In the following this active stereoisomeric component will always be designated B. As regards the steroids referred to in connection with the present invention the stereoisomeric mixture as well as the individual stereoisomeric components A and B have been investigated with regard to antiinflammatory activity in granulom test on rats subjected to adrenalectomy. The experimental procedure used corresponds largely to that described by G. Engelhardt: Arzneimittel-Forschung, I3, p. 588, I963. According to this procedure the test substances are applied topically in the implanted cotton wads. It is thereby possible to study the local antiinflammatory effect in granulomas and also systemic effects in the form of retrogression of thymus and inhibition of bodyweight growth.

Young male rats of the Sprague-Dawley strain weighing about I l-I30 g were subjected to adrenalectomy under ether narcosis. Two sterilized cotton wads of each about 6 mg were implanted simultaneously subcutaneously on the lateral side of the spinal. After awakening the animals were stored per cage and were supplied with normal food and l sodium chloride solution as drinking water. On the eighth test day the animals were sacrificed by ether marcosis. The granuloma formed around the cotton wads were carefully recovered and thymus and body weights were measured. The two granuloma from each animal were dried over night at 80C and weighed. After subtraction of the initial weight of the cotton wads the weight increase was used as a measure of the granulom growth.

The test substances were used dissolved in ethyl acetate. Under aseptic conditions 0.05 ml of Said solutions were injected into each of the cotton wads, whereafter the solvent was allowed to evaporate in the desiccator. Normally 3 concentrations of each test substance with the standard doses 3.3, 30 and 270 y/animal were investigated. Each test group normally comprised IO rats. The cotton wads of the control group were injected with only ethyl acetate, but were in other respects treated in the same way. When considering the effects of the test substances the average values of granulom growth, 'thymus weight and body weight increase day 0-8 were measured in each group in absolute figures 10 and in of the corresponding figure of the control group. Dose-response curves were drafted and used for estimating the doses giving reduction of granulom growth and of thymus weight and 25 decrease of body weight increase.

The results of the experiments carried out with the steroids in question are summarized in Table 3 below. From said table it is immediately clear, that difference in activity is found between the stereoisomeric components in each isomer pair, and that it is always the isomer last eluted from the gel column, which shows the highest activity. By means of the separation process of the present invention it has been possible to show that one of the stereoisomeric components, namely component B, shows a clearly stronger antiinflammatory effect than that obtained with the corresponding stereoisomeric mixture.

Irrespective of the interest to find steroid structures having a high activity there is a great demand for new compounds showing a better relation between antiinflammatory effect and the non-desired systemic effects, that may be observed after the resorption of the compounds. Thymus regression and inhibition of body growth may be seen as examples of such non-desired efiects. From the table it is clear that in order to obtain a good antiinflammatory effect (50 inhibition of granulom growth) it is necessary with regard to the reference substances Triamcinolone acetonide and Fluocinolone acetonide to resort to doses of such a level (about 125 and 50 y/animal, respectively) as to simultaneously result in a heavy decrease of thymus weight and body weight growth among the test animals. With regard to the compounds of the invention the doses needed for 50 inhibition of granuloma growth are, however, lower than or possibly of the same level as those giving a thymus regression or body growth inhibition.

Even if component A does not show an antiinflammatory effect as pronounced as that of corresponding component B it may in certain cases be more advantageous to use comp.) nent A as such instead of the isomeric mixture with regard to better characteristics regarding non-desired systemic effects.

Table 3 Compound prepared isomer Dose (y/animal) required to obtain 50% inhibition of 25% inhibition according to Example Grunulomu Thy- Body weight mus No. growth weight Increusc "I'riumcinolune acetonide I25 70 I00 I A+B I20 270 270 I A 270 I I5 I B 30 50 30 2 A+B 35 I00 I40 2 A 25 I30 90 2 B IO 60 I00 3 A+B I0 30 30 3 A 25 30 30 3 I! 3 I7 I00 4 AH! 3 I70 4 A 3 I00 I70 4 8 3 50 I00 5 A-I-B I7 I30 270 5 A 30 )0 270 5 B IO 90 270 Fluocinolnne acetonide 50 I4 20 7 A I5 I2 20 7 B IO 6 l5 8 AH! 5 I0 50 R A 6 I3 50 I4 5 4 I0 50 Prcdnucinolone acetonide 270 I05 270 acetonide A-t-B I00 I10 Table 3-continued Table summariving biological effects of investigated compounds Compound prepared lsomer Dose (-y/unimal] required to obtain SW34 inhibition of 25% inhibition according to Example (iranuloma Thy- Body Weight mus Nn. growth weight increase l2 A l25 I25 270 l2 8 4O 70 5 l 3 A+B It] 175 90 l 3 A 8 270 IOU l 3 B i 2 10 27" 16 A 5 70 45 l6 B 3 IO l0 I? A 7 45 20 I? B 3 l 3 21) iii A 3 70 33 l ii B 3 IU lll 2U A+H "l 20 It] A 3 9U 51) Ill H 3 2i] 5 ll A+B 7 it) 2 l A 3 7U 7O 2 l R 3 It] 5 22 A+B it) 5U 3U 22 A 3 9U 33 22 B 3 35 5 25 A-t-B 1 It) It) 25 A 3 l5 'll] 25 B 3 7 2t] 27 A+B 3 6U 4U 27 A 3 lllO IOU 27 B 3 60 35 The compounds may be used to treat lnflammatlon in EXAMPLE 2 any living mammalian animal body by administering thereto an effective anti-inflammatory amount of the 30 y 9g -P py ethylenedioxycompound in any suitable form and by any suitable P g -L B, nemode of administration, e.g. topically, orally, or parenw is claimed terally, in the same manner as their parent compounds, but generally with greater efficiency and therefore generally in lower dosages and according to somewhat lower dosage regimens.

As representative of living animal bodies which may be treated with the compounds and compositions of the invention, and according to the method of treating of 40 the invention, for alleviation of the same and/or similar conditions as those described, the following may be mentioned: domestic animals such as dogs and cats, farm animals such as horses, cows, sheep and goats.

Particularly preferred compounds are (Reference being had to component B throughout said examples):

1. A process for the resolution of stereoisomeric 35 mixtures (isomer pairs) of steroids having the general formula:

EXAMPLE 1 160:, l 7a-( 2 '-hydrogen-2 '-methyl )methylenedioxy-J- 5t) fluoropregnal .4-diene-l IB,2 l -diol-3,20-dione.

EXAMPLE 3 l6a,17a-(2-hydrogen-2'n-propyl)methylenedioxy-9- fluoropregna-l ,4-diene-l lB,2 l -diol-3,2()-dione.

wherein the 1,2-position is saturated or a double bond is present in that position, a double bond always being EXAMPLE 7 present in at least the 4,5 position, X and X, are indel6a,l7a-(2'-hydrogen-2'-methyl)methylenedioxy- P P Y Selected from hydrogen fluorine, 6a,9 diflu pyegna l 4-diene l 1 B,21-di l-3 2(). being selected from hydrogen and fluorine when X is di hydrogen and X being fluorine when X is fluorine, Z is selected from hydroxyl and esterified hydroxyl wherein the hydroxyl group is esterified with a member EXAMPLE 8 of the group consisting of phosphoric and sulphuric 16a.l7a-(2'-hydrogen-2'-n-propyl)methylenedioxyacids dicarboxylic acids having 2-l2 carbon atoms, bmQ-difluoropregna-l ,4-diene-l lB,2l-diol-3.20- pyrldine-3-carboxylic acid, pyridine-4-carboxylic acid,

dione. benzdfurane-Z-carboxylic acid, and menthoxy-methylcarboxylic acid, and lower-alkanoic acids, and R is selected from alkyl groups with straight or branched hydrocarbon chains having ll carbon atoms, into their Stereoisomeric components with regard to the space orientation of the substituents on the 2'-carbon atom of the dioxolane ring, characterized by subjecting the stereoisomeric mixture to gel filtration using crosslinked dextran or vinylacetatepolymer gel, the components in view of different retention volumes being separated and being separately recoverable.

2. A process according to claim 1, characterized by carrying out the gel filtration on a cross-linked dextran gel.

3. A process according to claim 2, characterized in carrying out the gel filtration on Sephadex LH 20.

4. A process according to claim 1, characterized by carrying out the gel filtration on a copolymer of vinyl acetate.

5. A process according to claim 4, characterized by carrying out the gel filtration on Merckogel OR-PVA.

6. A process according to any of claim 1, characterized by carrying out the gel filtration by means of an eluating agent selected from halogenated hydrocarbons, ethers and esters.

7. A process according to claim 6, characterized by carrying out the gel filtration with an eluating agent selected from ethyl acetate, acetonitrile, methylene chloride and chloroform.

8. Stereoisomeric component B of a stereoisomeric mixture (isomeric pair) of a steroid having the general formula:

wherein the l,2-position is saturated or a double bond |s present in that position, a double bond always being present in at least the 4,5-position, X and X are independently selected from hydrogen and fluorine, X I being selected from hydrogen and fluorine when X is hydrogen and X, being fluorine when X is fluorine, Z 18 selected from hydroxyl and esterified hydroxyl wherein the hydroxyl group is esterified with a member of the group consisting of phosphoric and sulphuric acids, dlcarboxylic acids having 2 l2 carbon atoms, pyridlne-3-carboxylic acid, pyridine-4-carboxylic acid, benzofurane-2-carboxylic acid, and menthoxy-methylcarboxyhc acid, and lower alkanoic acids, and R is 14 selected from alkyl groups with straight or branched hydrocarbon chains, having 1-10 carbon atoms, said component B being the isomer of the isomer pair showing the greatest relative rotary power or having the greatest retention volume in gel filtration using a crosslinked dextran gel.

9. Stereoisomeric component according to claim 8 characterized in that R is an alkyl group having l-6 carbon atoms.

10. Stereoisomeric component according to claim 9, wherein Z is hydroxyl esterified with an acid selected from acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid, trimethyl acetic acid, hexanoic acid, tert. butylacetic acid and octanoic acid.

ll. Stereoisomeric component according to claim 9, wherein Z is hydroxyl esterified with an acid selected from pyridine-3-, pyridine-4-, benzofurane-2-carboxylic acid and methoxymethylcarboxylic acids.

12. Stereoisomeric component according to claim 9, wherein Z is hydroxyl esterifled with an acid selected from dicarboxylic acids, preferably such acids having 2-l2 carbon atoms.

13. Stereoisomeric component according to claim 9, wherein Z is hydroxyl esterified with an acid selected from phosphoric and sulphuric acids.

14. Stereoisomeric component B according to claim 8, which is l6a,l7a-(2-hydrogen-2-methyl)methylenedioxy-Q-fluoropregnal ,4-diene-l l 3,2 l-diol-3,20 dione.

15. Stereoisomeric component B according to claim 8, which is 160,17a-(2'-hydrogen-2'-n-propyl)methylenedioxy-9-fluoropregna-1,4-diene-l l3,2 l-diol-3 ,20- dione.

l6. Stereoisomeric component B according to claim 8, which is 16a,l7a (2'-hydrogen-2'-methyl)methylenedioxy-6a,9-difluoropregna l ,4-diene-l l 3,2 l-diol- 3,20-dione.

l7. Stereoisomeric component B according to claim lenedioxy-6a,9-difluoropregnal ,4-diene-l l3,2 l -diol- 3,20-dione.

l8. Stereoisomeric component B according to claim 8, which is l6a,l7a-(2'-hydrogen-2-n-propyl)methylenedioxypregnal ,4-diene-l l3,2 l -diol-3,20-dione.

l9. A process according to claim 1, wherein the steroid is l 6a,17a-(2'-hydrogen-2'-methyl)methylenedioxy-9-fluoropregnal ,4-diene-l l3,2 l-diol-3,20- dione.

20. A process according to claim 1, wherein the steroid is l 7a-(2'-hydrogen-2 '-n-propyl )methylenedioxy-9-fluoropregnal ,4-diene-l l3,2 l -diol-3,20- dione.

2]. A process according to claim I, wherein the steroid is 1601,] 701-(2'-hydrogen-2'methyl)methylenedioxy-6a,9-difluoropregnal ,4-dienel l 3,2 l-diol- 3,20-dione.

22. A process according to claim 1, wherein the steroid is 160e,]7a-(2'-hydrogen-2-n-propyl)methylenedioxy-6a,9-difluoropregnal ,4-diene-l l3,2 l -diol- 3,20-dione.

23. A process according to claim 1, wherein the steroid is 1601,] 7a-( 2 -hydrogen-2 -n-propyl )methylenedioxypregnal ,4-diene-l l3,2 l -diol-3,20-dione.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,928,326 Dated December 23, 1975 Inventor(s) Ralph Lennart Brattsand et al.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[30] Foreign Application Priority Data May 19, 1972 Sweden 6645/72 Primary Examiner Elbert L. Roberts Column 9, line 24 "maroosis" should be naroosis Col. 10, last line of table "acetonide" should be l2 Signed and Scaled this Tenth Day of August 1976 [SEAL] Arrest.-

RUTI'I C. MASON C. MARSHALL DANN Am'fl g Offl'fl Commissioner uflatenls and Trademark: 

1. A process for the resolution of stereoisomeric mixtures (isomer pairs) of steroids having the general formula:
 2. A process according to claim 1, characterized by carrying out the gel filtration on a cross-linked dextran gel.
 3. A process according to claim 2, characterized in carrying out the gel filtration on Sephadex LH
 20. 4. A process according to claim 1, characterized by carrying out the gel filtration on a copolymer of vinyl acetate.
 5. A process according to claim 4, characterized by carrying out the gel filtration on Merckogel OR-PVA.
 6. A process according to any of claim 1, characterized by carrying out the gel filtration by means of an eluating agent selected from halogenated hydrocarbons, ethers and esters.
 7. A process according to claim 6, characterized by carrying out the gel filtration with an eluating agent selected from ethyl acetate, acetonitrile, methylene chloride and chloroform.
 8. STEROISMERIC COMPONENT B OF A STEROISOMERIC MIXTURE ISOMERIC PAIR) OF A STEROID HAVING THE GENERAL FORMULA:
 9. Stereoisomeric component according to claim 8 characterized in that R is an alkyl group having 1-6 carbon atoms.
 10. Stereoisomeric component according to claim 9, wherein Z is hydroxyl esterified with an acid selected from acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid, trimethyl acetic acid, hexanoic acid, tert. butylacetic acid and octanoic acid.
 11. Stereoisomeric component according to clAim 9, wherein Z is hydroxyl esterified with an acid selected from pyridine-3-, pyridine-4-, benzofurane-2-carboxylic acid and methoxymethylcarboxylic acids.
 12. Stereoisomeric component according to claim 9, wherein Z is hydroxyl esterified with an acid selected from dicarboxylic acids, preferably such acids having 2-12 carbon atoms.
 13. Stereoisomeric component according to claim 9, wherein Z is hydroxyl esterified with an acid selected from phosphoric and sulphuric acids.
 14. Stereoisomeric component B according to claim 8, which is 16 Alpha ,17 Alpha -(2''-hydrogen-2''-methyl)methylenedioxy-9-fluoropregna-1,4-diene-11 Beta ,21-diol-3,20-dione.
 15. Stereoisomeric component B according to claim 8, which is 16 Alpha ,17 Alpha -(2''-hydrogen-2''-n-propyl)methylenedioxy-9-fluoropregna-1,4-diene-11 Beta ,21-diol-3,20-dione.
 16. Stereoisomeric component B according to claim 8, which is 16 Alpha ,17 Alpha -(2''-hydrogen-2''-methyl)methylenedioxy-6 Alpha ,9-difluoropregna-1,4-diene-11 Beta ,21-diol-3,20-dione.
 17. Stereoisomeric component B according to claim 8, which is 16 Alpha ,17 Alpha -(2''-hydrogen-2''-n-propyl)methylenedioxy-6 Alpha ,9-difluoropregna-1,4-diene-11 Beta ,21-diol-3,20-dione.
 18. Stereoisomeric component B according to claim 8, which is 16 Alpha ,17 Alpha -(2''-hydrogen-2''-n-propyl)methylenedioxypregna-1,4-diene-11 Beta ,21-diol-3,20-dione.
 19. A process according to claim 1, wherein the steroid is 16 Alpha ,17 Alpha -(2''-hydrogen-2''-methyl)methylenedioxy-9-fluoropregna-1,4-diene-11 Beta ,21-diol-3,20-dione.
 20. A process according to claim 1, wherein the steroid is 16 Alpha ,17 Alpha -(2''-hydrogen-2''-n-propyl)methylenedioxy-9-fluoropregna-1,4-diene-11 Beta ,21-diol-3,20-dione.
 21. A process according to claim 1, wherein the steroid is 16 Alpha ,17 Alpha -(2''-hydrogen-2''-methyl)methylenedioxy-6 Alpha , 9-difluoropregna-1,4-diene-11 Beta ,21-diol-3,20-dione.
 22. A process according to claim 1, wherein the steroid is 16 Alpha ,17 Alpha -(2''-hydrogen-2''-n-propyl)methylenedioxy-6 Alpha ,9-difluoropregna-1,4-diene-11 Beta ,21-diol-3,20-dione.
 23. A process according to claim 1, wherein the steroid is 16 Alpha ,17 Alpha -(2''-hydrogen-2''-n-propyl)methylenedioxypregna-1, 4-diene-11 Beta ,21-diol-3,20-dione. 